Potato planters from the prior art have not addressed the difficulties created by the momentum of the seed pieces when planting potatoes at high speed. For example, the following documents describe potato planters that are handling seed pieces one-by-one using a series of buckets mounted along a chain. The chain rotates at a same speed as the ground speed of the planter. As the chain rotates, the buckets drop seed pieces in a furrow at spaced intervals. These documents are:
U.S. Pat. No. 3,570,424 issued to J. H. Wigham on Mar. 16, 1971;
U.S. Pat. No. 3,690,511 issued to J. H. Wigham on Sep. 12, 1972;
U.S. Pat. No. 6,244,201 issued to W. Mauch et al., on Jun. 12, 2001.
Similarly, other types of agricultural planters are not addressing the momentum of seed pieces. The following documents describe seed planters having a press wheel mounted thereto for pressing the soil of the furrow against the seeds. The press wheels are mounted far behind the seed-drop chute and have no effect on the momentum of the seeds. These agricultural planters are described in the following documents:
U.S. Pat. No. 4,493,272 issued to L. M. Rouhotas, on Jan. 15, 1985;
U.S. Pat. No. 4,579,071 issued to D. J. Johnson on Apr. 1, 1986.
The documents found in the prior art comprise fixed-speed potato planters and agricultural planters that are designed to handle small seeds such as corn, wheat and other grains and soybeans, wherein the mass of these seeds is very low as compared to seed potatoes. Therefore, a search of the prior art has not given any suggestion for planting potatoes at higher speed than those used at the present time.
Different from cereals, corn, and bean crops, potatoes are not grown from seeds per se, which are relatively small in size and have little mass. Potatoes are grown commercially by farmers from cutting tubers or seed potatoes from the previous year's crop. When seed potatoes are cut into “seed pieces” or “sets” they can weigh from 1 oz., or less to 3½ oz., or more. The seed run can also contain small round uncut seed potatoes mixed in with these larger irregular-shaped cut seed pieces.
“Seed potato”; “seed piece”; “set” and “potato seed piece” are used interchangeably in this document, to designate a whole tuber or a portion thereof that is used to germinate a potato plant.
Potato planters in general are used to separate and release seed pieces at a predetermine spacing in a row. Common spacings are 10, 12, 14, 18 and up to 24 inch. Most potato planters in the industry can achieve very good results at slow ground speeds. However, the seed spacing becomes inconsistent when these planters are pulled at ground speeds exceeding 2.5 to 2.8 mph. After the seed is released at high speed, it falls into the furrow and rolls until it loses all of its forward momentum. This is called “set roll”. A certain amount of set roll would be acceptable if all the seed pieces had the same amount of set roll. That is not the case, however. In North America, growers usually cut their seed potatoes in parts which means that the seed pieces do not have an uniform shape, size and weight, and therefore, not the same ability to roll.
It is well known that when planting speeds exceed 2.5 mph, set roll begins to greatly affect the seed spacings. Despite of this, most potato growers don't go that slow during planting. Most growers want to take advantage of a sunny and dry period in mid-May usually, to plant their fields as early and as quickly as possible to maximize the number of growing days before harvest. Therefore, a majority of potato growers in Eastern Canada plant their fields at high speeds such as 4, 5 and even 6 mph when planting Russet-Burbanks™ or Gems™ varieties, for examples. These varieties are planted at 14 inches to 18 inches apart. Although the mechanisms of common planters work well at high speeds, these planters cannot release the right amount of seeds per acre, at the right spacing when planting speed exceeds 2.5 to 2.8 mph.
Seed piece spacing is critical to achieve an ideal yield per acre from a field. When the plants are too close to each other, the crop potatoes are small. When the plants are too far apart, the yield per acre is low and the crop potatoes may be larger than the ideal market size.
Therefore there is a need in the potato growing industry for a method of reducing set roll when planting seed pieces at higher speeds than the present limitations.